Vamos para um pouco de código o/

Imports

%matplotlib inline
import collections
import cv2
import dlib
from imutils import face_utils
from matplotlib import pyplot as plt
import numpy as np

# from google.colab.patches import cv2_imshow

Códigos!!!

Dlib detecção de rosto

Preparativos...

detector = dlib.get_frontal_face_detector()
predictor = dlib.shape_predictor('helpers/'
                                 'shape_predictor_68_face_landmarks.dat')

O poder do Dlib

image_01 = cv2.imread('persons/bolsonaro.png')
image_01 = cv2.cvtColor(image_01, cv2.COLOR_BGR2RGB)

plt.figure(figsize=(10, 10))
plt.imshow(image_01)
plt.show()

Capturar a região do rosto

face = face_detection(image_01, detector)

plt.figure(figsize=(10, 10))
plt.imshow(face)
plt.show()

Será que continua capturando o rosto se a imagem estiver alterada?

kernel = np.ones((7, 7),np.float32)/25
result_2d_filter = cv2.filter2D(image_01,-1,kernel)

plt.figure(figsize=(10, 10))
plt.imshow(result_2d_filter)
plt.show()

face = face_detection(result_2d_filter, detector)

plt.figure(figsize=(10, 10))
plt.imshow(face)
plt.show()

rows, cols, _ = image_01.shape

M = cv2.getRotationMatrix2D((cols/2,rows/2), 45, 1)
rotate_image_01 = cv2.warpAffine(image_01,M,(cols,rows))

plt.figure(figsize=(10, 10))
plt.imshow(rotate_image_01)
plt.show()

face = face_detection(rotate_image_01, detector)

plt.figure(figsize=(10, 10))
plt.imshow(face)
plt.show()

E se tiver mais de um rosto?

image_02 = cv2.imread('persons/bolsonaro_02.jpg')
image_02 = cv2.cvtColor(image_02, cv2.COLOR_BGR2RGB)

plt.figure(figsize=(10, 10))
plt.imshow(image_02)
plt.show()

Será que ele detecta mesmo todos os rostos?

faces = face_detection(image_02, detector)

plt.figure(figsize=(10, 10))
plt.imshow(faces)
plt.show()

Pontos de interesse do rosto

Vamos ver esses pontos nas imagens

land = landmarks_detection(image_02, detector, predictor)

plt.figure(figsize=(15, 15))
plt.imshow(land)
plt.show()

land = landmarks_draw(image_02, detector, predictor)

plt.figure(figsize=(10, 10))
plt.imshow(land)
plt.show()

Regiões de interesse do rosto

land = facial_landmarks(image_01, predictor, detector)

plt.figure(figsize=(10, 10))
plt.imshow(land)
plt.show()

Vamos brincar um pouco com essas regiões de interesse... ou tentar.

overlay = image_01.copy()
pts = get_coordinates(image_01, 'mouth', detector, predictor)[0]

for l in range(1, len(pts)):
    ptA = tuple(pts[l - 1])
    ptB = tuple(pts[l])
    cv2.line(overlay, ptA, ptB, (0, 255, 0), 2)

plt.figure(figsize=(10, 10))
plt.imshow(overlay)
plt.show()

Ops... Vamos tentar de novo...

def get_mouth(image, offset=0):
    overlay = image.copy()
    pts = get_coordinates(image, 'mouth', detector, predictor)[0]
    
    ptA = tuple(pts[0])  # Canto esquerdo da boca
    ptB = tuple(pts[6])  # Canto direito da boca

    ptC = tuple(pts[3])  # Canto superior da boca
    ptD = tuple(pts[9])  # Canto inferior da boca

    h = abs(ptC[1] - ptD[1])
    w = abs(ptA[0] - ptB[0])

    # img[y:y+h, x:x+w]
    region = overlay[ptA[1] - offset: ptA[1] + h,
                     ptA[0] - offset: ptA[0] + w + offset]
    
    return region, ptB, ptD, w
    

overlay, ptB, ptD, w = get_mouth(image_01)

plt.figure(figsize=(5, 5))
plt.imshow(overlay)
plt.show()

overlay, ptB, ptD, w = get_mouth(image_01, offset=50)

plt.figure(figsize=(5, 5))
plt.imshow(overlay)
plt.show()

Que tal um pouco de barba?

sticker_beard = cv2.imread('stickers/barba_02.png', -1)
watermark_beard = cv2.resize(sticker_beard, None, fx=0.4, fy=0.4)

plt.figure(figsize=(10, 10))
plt.imshow(watermark_beard)
plt.show()

def insert_sticker(image, watermark, pt1, pt2, w, offset_h, offset_w, div, mult):
    frame = cv2.cvtColor(image, cv2.COLOR_RGB2BGRA)
    frame_h, frame_w, frame_c = frame.shape

    # overlay with 4 channels BGR and Alpha
    overlay = frame.copy()
    watermark_h, watermark_w, watermark_c = watermark.shape

    # replace overlay pixels with watermark pixel values
    for i in range(0, watermark_h):
        for j in range(0, watermark_w):
            if watermark[i,j][3] != 0:
                w_offset = pt1 - (w*mult) - offset_w
                h_offset = pt2 - (int(pt2/div) + offset_h)
                overlay[h_offset + i, w_offset + j] = watermark[i, j]

    return cv2.cvtColor(overlay, cv2.COLOR_BGRA2RGB)

overlay_01 = insert_sticker(image_01, watermark_beard, ptB[0],
                            ptD[1], w, 30, 0, 5, 2)

plt.figure(figsize=(10, 10))
plt.imshow(overlay_01)
plt.show()

Ou um óculos?

stickers_gl = cv2.imread('stickers/oculos_01.png', -1)
watermark_gl = cv2.resize(stickers_gl, None, fx=0.6, fy=0.6)

plt.figure(figsize=(10, 10))
plt.imshow(cv2.cvtColor(watermark_gl, cv2.COLOR_BGRA2RGB))
plt.show()

Clipping input data to the valid range for imshow with RGB data ([0..1] for floats or [0..255] for integers).

Precisamos saber onde está os olhos...

def get_right_eye(image, offset=0):
    overlay = image.copy()
    pts = get_coordinates(image, 'right_eye', detector, predictor)[0]

    ptA = tuple(pts[0])  # Canto esquerdo do olho
    ptB = tuple(pts[3])  # Canto direito do olho

    ptC = tuple(pts[1])  # Canto superior do olho
    ptD = tuple(pts[5])  # Canto inferior do olho

    h = abs(ptC[1] - ptD[1])
    w = abs(ptA[0] - ptB[0])

    # img[y:y+h, x:x+w]
    region = overlay[ptA[1] - offset: ptA[1] + h,
                     ptA[0] - offset: ptA[0] + w + offset]
    
    return region, ptB, ptD, w
    

offset = 30
overlay, ptB, ptD, w = get_right_eye(image_01, offset)

plt.figure(figsize=(5, 5))
plt.imshow(overlay)
plt.show()

E agora vamos ajudar ele a enxergar melhor :)

overlay_02 = insert_sticker(image_01, watermark_gl, ptB[0], ptD[1], w, offset, 0, 2, 3)

plt.figure(figsize=(10, 10))
plt.imshow(overlay_02)
plt.show()

O resultado final

overlay_02 = insert_sticker(overlay_01, watermark_gl, ptB[0],
                            ptD[1], w, offset, 0, 2, 3)

plt.figure(figsize=(10, 10))
plt.imshow(overlay_02)
plt.show()

Outros resultados \o/

overlay_03 = insert_sticker(image_03, watermark_gl, ptB[0], ptD[1],
                            w, offset, offset, 2, 2)

plt.figure(figsize=(10, 10))
plt.imshow(overlay_03)
plt.show()

overlay_04 = insert_sticker(image_04, watermark_mus, ptB[0],
                            ptD[1], w, offset, -20, 4, 2)

plt.figure(figsize=(10, 10))
plt.imshow(overlay_04)
plt.show()

overlay_05 = insert_sticker(image_05, watermark_dbz, ptB[0],
                            ptD[1], w, offset, -offset*3, 4, 2)

plt.figure(figsize=(10, 10))
plt.imshow(overlay_05)
plt.show()

offset = 70

overlay_06 = insert_sticker(image_06, watermark_hair, ptB[0],
                            ptD[1], w, offset, offset, 2, 2)

plt.figure(figsize=(10, 10))
plt.imshow(overlay_06)
plt.show()